A known compound which is similar to the antibiotic substances according to the present invention in physiochemical properties is CC-1065 as reported in D. G. Martin et al., J. Antibiotics, Vol. 34, 1119-1125 (1981). The antibiotic substances according to the present invention have been confirmed to clearly differ from CC-1065 in physiochemical properties and thereby to be novel antimicrobial substances.
A number of antimicrobial and antitumor substances have hitherto been reported, and some of them have been put into practical use as antimicrobials or anticancer agents. However, there are many unsolved problems in their application to the field of chemotherapy.